how to do this??

[GamerDeMTA]

I want to put in all the screen an Image when a player clicks a button from a GUI, but only for two minutes, also change the Gamemode FROM THE USER WHO DOES IT, not root, to 0.6.

[^.^]

Well for first if you want to create an Image for 2 minutes use a timer and then print it on the playerscreen with a GUIImage otherwise you can use the dxDraw Functions and calculate the showing time with the tickcount.

For your second problem there is something difficult. You can't change the gamemode for one player. If you want to do that it's like an arenagameode. So you have to work more clientside, ...

If you want to use the dxFunctions

dxDrawImage 
getTickCount 

For GUI

guiCreateStaticImage 
setTimer